Engine fuel injector



.1. W. Dow 2,148,192

Filed May 27, 1938 2 Sheets-Sheet l ENGINE FUEL INJECTOR Feb. 21, 1939.

Feb. 21, 1939. 1, W. DOW 2,148,192

ENGINE FUEL INJECTOR Filed May 27, 1958 2 Sheets-Sheet 2 5 a 4a 59 y Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE ENGINE FUEL INJECTOR John W. Dow, Sioux City, Iowa Application May 27, 1938, Serial No. 210,490

3 Claims. (Cl. 299-1072) The invention relates to engine fuel injectors of the general type in which a reciprocatory plunger is operable within a casing and connected with the engine cylinder head for injecting a :a spray of liquid fuel into the compressed and heated air within the engine cylinder.

The principal object of the invention is to provide a generally simplified construction, yet one which will be highly eicient, may be easily lo disassembled for cleaning whenever required, and will facilitate replacement of any required parts from time to time.

A further object is to provide an injector in which no fuel lies dormant in the injector tip,

l' to give the engine a clean exhaust, quick cut-0E and instant starting at any temperature.

With the foregoingl and minor objects in View, the invention-resides in the novel subject matter hereinafter described and claimed, description :2o being accomplished by reference to the accompanying drawings.

Fig. l is a vertical sectional view through one form of the injector showing the plunger in lowered position.

5 Fig. 2'is a horizontal sectional View as indicated by line 2--2 of Fig. 1.

Fig. 3 is a detail vertical section showing the plunger in raised position.

Fig. 4 is a top plan View of the ring constituting :jfl one element of the injector.

Fig. 5 is a sectional View on line 5-5 of Fig. 4.

Fig. 6 is an end elevation of the cylindrical block forming another element of the injector.

Fig. 'l is a side elevation of said cylindrical block.

Fig. 8 is a View similar to Fig. 1 but illustrating a more simple construction, the plunger being shown in lowered position.

Fig. 9 is a detail sectional view showing the 40 plunger in raised position.

Fig. 10 is a horizontal section on line Ill- Ill of Fig. 8.

Fig. 11 is an end elevation of the cylindrical block shown in Figs. 8 to 10.

4,; Fig. 12 is a side elevation of said cylindrical block.

In both forms of construction, a tubular casing I5 is shown formed from upper and lower sections I6 and I'I having abutting flanges I8 jointly 50 forming a body portion to be secured to the Yengine cylinder head. The lower section I1 is formed with a longitudinal fuel port I9 tapped at its inlet end for connection with a fuel line 20, and provided with an appropriate check valve 55 2l. The lower end portion of this section I'l is threaded at 22 for engagement with a cap 23 having central fuel spray means 24, and the lower extremity of said section I'I is formed with a radial fuel groove 25 communicating with the In both forms of construction, I have `5 also provided a plunger 2t having a reduced lower end portion 21, the lower extremity 28 of which is conical to constitute a fuel cut-off valve as hereinafter explained. At the juncture of the reduced portion 21 with the major portion of the plunger '26, a downwardly facing shoulder 29 is provided. A suitable spring exerting an upward force on the plunger 26, and the usual push rod and rocker arm, or similar means is provided for depressing the plunger to inject a spray of fuel into the engine cylinder.

In the'form of construction shown in Figs. 1 to 7, a cylindrical block 30 abuts the lower end of the casing section I 'I and extends across the open lower side of the fuel groove 25, said block having a central bore 3l which slidably receives the reduced portion 21 of the plunger 20. 32 of the upper end of the block 30 immediately surrounding the bore 3|, constitutes an upwardly facing shoulder, and said block is provided with longitudinal fuel ports 33 extending from this shoulder through the lower end of said block. Abutting this lower end of block 30, is a ring 3M having a conical seat 35`which communicates with the fuel spray means 24 and is cooperable with the conical lower end 28 of the plunger 25. upper side of the ring 34 is provided with an annular groove 36 communicating with the ports 33, and said ring is formed also with acute angular fuel ports 31 which extend from said groove 36 to said seat 35.

The downwardly facing shoulder 29 of the plunger 2S and the upwardly facing shoulder 32 of the block 30, are cooperable in. forming a chamber 38 (Fig. 3) which receives fuel from the port I9 upon ascent of the plunger 26, as seen in said View. Upon descent of the plunger 26, this chamber 3B expels the liquid fuel through the ports 33, groove 36, ports 3l, seat 35 and spray means 24, into the` heated air in the enginev cylinders, and when the plunger is fully lowered, the conical plunger end 28 tightly engages said seat 35, sealing the interior of the injector from communication with the engine cylinder during comis provided The portion The block 30 and ring 34 are both contained in the cap 23 which is threaded at 22 upon the lower end of the casing section I1, and should these parts require cleaning, it will be seen that they may be easily removed. Similarly, new

parts may be quickly and easily substituted whenever advisable.

In the form of construction shown in Figs. 8 to 12, the cap 23 is itself provided with a conical seat 35a cooperable with the plunger end 28 and communicating with the spray means 24, and a cylindrical block 303L is alone confined within said cap, being held by the latter against the lower end of the tubular casing. The side wall of -the bore 3W of the block 30a, which bore receives the reduced plunger portion 21, is formed with longitudinal grooves 33a which extend from the shoulder 32a to the lower end of the block, the lower ends of said grooves being in communication with the seat 35a.

The shoulder 29 of the plunger 26 coacts with the shoulder 32EL to provide the chamber 38a. Upon ascent of the plunger, this chamber re ceives fuel and upon descent of said plunger, said chamber discharges said fuel through the grooves 33a, seat 35a and spray means 24. When the plunger reaches its final lowered position, its conical end 28 tightly seats in the seat 35a, cutting off communication between the engine and the interior of the injector during combustion,

It will be seen that both forms of construction are simple and inexpensive, may be easily manufactured and installed, easily disassembled and cleaned, and easily repaired. Then too, it is insured that the engine shall have clean exhaust, quick cut-off, and instantaneous starting.

While the exact details above described, may be followed if desired, Variations may, of course, be made within the scope of the invention as claimed.

It may be well to add that 39 is merely a fuel drain port leading from the upper casing section I6 to a drain line 40, for carrying off any fuel which may leak upwardly past the plunger 26.

I claim:

1. An engine fuel injector comprising an elongated tubular casing having a longitudinal fuel passage, the lower end of said tubular casing being provided with a fuel groove extending from the lower end of said fuel passage to the interior of said tubular casing, a block abutting the lower end of said tubular casing and extending across the open lower side of said fuel groove, said block having a bore axially alined with said tubular casing and of a diameter less than the internal diameter of said casing, whereby a portion of the upper end of said block constitutes an upwardly facing shoulder projecting inwardly from the casing, a cap containing said block and secured to the lower end of said casing, said cap having fuel spray means, fuel conducting means extending from said shoulder to said fuel spray means and including a fuel passage in said block and a conical seat communicating with said fuel spray means, and a plunger slidable in saidV casing and said bore of said block and having a conical lower end cooperable with said conical seat, said plunger having a downwardly facing shoulder cooperable with said upwardly facing shoulder in forming a chamber which receives fuel from said groove upon ascent of said plunger and discharges said fuel through said fuel conducting means and said fuel spray means upon descent of said plunger.

2. An engine fuel injector comprising a tubular casing, a block abutting the lower end of said tubular casing and having a bore axially alined therewith, the diameter of said bore being less than the internal diameter of said tubular casing, whereby a portion of the upper end of Vsaid block constitutes an upwardly facing shoulder projecting inwardly from the casing, said casing being provided with a fuel passage opening into its interior directly over said upwardly facing shoulder, a ring abutting the lower end of said block, the inner edge of said ring being inclined to provide a conical seat, said block and ring being provided with communicating fuel passages extending from said upwardly facing shoulder to said seat, a cap containing said block and ring and secured to said casing, said cap having fuel spray means communicating with said conical seat, and a plunger slidable in said tubular casing and said bore of said block and having a conical lower end cooperable with said conical seat, said plunger having a downwardly facing shoulder cooperable with said upwardly facing shoulder in forming a chamber which receives fuel from said fuel passage of said casing upon ascent of the plunger and discharges fuel through said fuel passages of said block and ring and through said fuel spray means upon descent of said plunger.

3. An engine fuel injector comprising a tubular casing, a block abutting the lower end of said tubular casing and having a bore axially alined therewith, the diameter of said bore being less than the internal diameter of said tubular casing, whereby a portion of the upper end of said block constitutes an upwardly facing shoulder projecting inwardly from said tubular casing, said casing being provided with a fuel passage opening into its interior directly over said upwardly facing shoulder, the wall of said bore of said block being provided with a longitudinal fuel groove extending from said upwardly facing shoulder to the lower end of the block, a cap containing said block and secured to said casing, said cap having a central conical seat communicating directly with the lower end of said fuel groove, said cap being also provided with fuel spray means communicating with said conical seat, and a plunger slidable in said tubular casing and said bore of said block and having a conical lower end cooperable with said conical seat, said plunger having a downwardly facing shoulder cooperable with said upwardly facing shoulder in forming a chamber which receives fuel from said 'fuel passage of said casing during ascent of said plunger and discharges fuel through said fuel groove, conical seat and fuel spray means upon descent of said plunger.

JOHN W. DOW. 

